Sensation and Perception

Question 1

receptive field

Answer 1

part of the world that triggers a particular neuron

Question 2

sensory transduction

Answer 2

physical sensation changed into electrical messages

Question 3

nativist theory

Answer 3

perception and cognition are innate

Question 4

structuralist theory

Answer 4

perception is the sum of sensory input. bottom-up processing

Question 5

Gestalt theory

Answer 5

perception - people see the world as organized wholes - top-down processing

Question 6

rods

Answer 6

sensitive to dim light. concentrated along sides

Question 7

cones

Answer 7

concentrated in center (fovea) - greatest visual acuity. fewer cones per ganglion cell than rods

Question 8

Where does light travel after the receptors (rods and cones)?

Answer 8

horizontal cells, bipolar cells, amacrine cells, ganglion cells

Question 9

optic chiasm

Answer 9

visual pathways are 50% crossed. stimulus in LVF is processed in right brain

Question 10

where does information travel after optic chiasm?

Answer 10

striate cortex to visual association areas of the cortex

Question 11

theories for seeing color

Answer 11

opponent process theory in the lateral geniculate body: cones that respond to blue-yellow and cones that respond to red-green

tri-color theory in the retina: cones that respond to red, blue or green

Question 12

lateral inhibition

Answer 12

when a receptor cell is stimulated, others nearby are inhibited. prevents repetitive info being sent to the brain, lets us see contrast

Question 13

Hermann von Helmholtz

Answer 13

famous for his theory of color blindness, and for his place-resonance theory (different parts of the basilar membrane respond to different frequencies)

Question 14

Hubel & Wiesel

Answer 14

cells in visual cortex complex and specialized, e.g. some cells respond only to vertical lines (cat experiment)

Question 15

motion parallax

Answer 15

how movement is perceived through displacement of objects, and how this motion seems to be different speeds depending on distance of object

Question 16

why do we see afterimages?

Answer 16

fatigued receptors - once one side (e.g. of black-white) is overstimulated and fatigued, it can no longer respond and is overshadowed by its opposite

Question 17

pragnanz

Answer 17

Gestalt idea that experience will be organized as meaningful, symmetrical and simple

• closure: complete incomplete figures
• proximity: group close figures
• continuation
• symmetry
• constancy
• minimum principle: tendency what to see what is easiest/logical

Question 18

autokinetic effect

Answer 18

single point of light will appear to shake because of the constant movement of our eyes

Question 19

Purkinje shift

Answer 19

perceived color brightness changes with level of light in room

Question 20

thresholds

Answer 20

absolute - minimum amount of a stimulus that can be detected
terminal - maximum
differential - minimum difference that must occur between two stimuli for them to be perceived as different

Question 21

frequency that humans best hear

Answer 21

around 1000 Hz

Question 22

outer ear

Answer 22

pinna (part we see) and auditory canal

Question 23

middle ear

Answer 23

tympanic membrane, ossicles: malleus, incus, stapes

MIS

Question 24

inner ear

Answer 24

oval window, cochlea (basilar membrane, organ of corti), vestibular sacs

Question 25

touch receptors

Answer 25

free nerve endings detect pain and temperature Meissner's corpuscles detect touch Pacinian corpuscles detect displacements of skin